------------------------------------------------------------------------------- |-- Module : System.Exit-- Copyright : (c) The University of Glasgow 2001-- License : BSD-style (see the file libraries/base/LICENSE)-- -- Maintainer : libraries@haskell.org-- Stability : provisional-- Portability : portable---- Exiting the program.-------------------------------------------------------------------------------moduleSystem.Exit(ExitCode(ExitSuccess,ExitFailure),exitWith-- :: ExitCode -> IO a,exitFailure-- :: IO a,exitSuccess-- :: IO a)whereimportPrelude#ifdef __GLASGOW_HASKELL__importGHC.IOimportGHC.IO.Exception#endif#ifdef __HUGS__importHugs.Prelude(ExitCode(..))importControl.Exception.Base#endif#ifdef __NHC__importSystem(ExitCode(..),exitWith)#endif-- ----------------------------------------------------------------------------- exitWith-- | Computation 'exitWith' @code@ throws 'ExitCode' @code@.-- Normally this terminates the program, returning @code@ to the-- program's caller.---- On program termination, the standard 'Handle's 'stdout' and-- 'stderr' are flushed automatically; any other buffered 'Handle's-- need to be flushed manually, otherwise the buffered data will be-- discarded.---- A program that fails in any other way is treated as if it had-- called 'exitFailure'.-- A program that terminates successfully without calling 'exitWith'-- explicitly is treated as it it had called 'exitWith' 'ExitSuccess'.---- As an 'ExitCode' is not an 'IOError', 'exitWith' bypasses-- the error handling in the 'IO' monad and cannot be intercepted by-- 'catch' from the "Prelude". However it is a 'SomeException', and can-- be caught using the functions of "Control.Exception". This means-- that cleanup computations added with 'Control.Exception.bracket'-- (from "Control.Exception") are also executed properly on 'exitWith'.---- Note: in GHC, 'exitWith' should be called from the main program-- thread in order to exit the process. When called from another-- thread, 'exitWith' will throw an 'ExitException' as normal, but the-- exception will not cause the process itself to exit.--#ifndef __NHC__exitWith::ExitCode->IOaexitWithExitSuccess=throwIOExitSuccessexitWithcode@(ExitFailuren)|n/=0=throwIOcode#ifdef __GLASGOW_HASKELL__|otherwise=ioError(IOErrorNothingInvalidArgument"exitWith""ExitFailure 0"NothingNothing)#endif#endif /* ! __NHC__ */-- | The computation 'exitFailure' is equivalent to-- 'exitWith' @(@'ExitFailure' /exitfail/@)@,-- where /exitfail/ is implementation-dependent.exitFailure::IOaexitFailure=exitWith(ExitFailure1)-- | The computation 'exitSuccess' is equivalent to-- 'exitWith' 'ExitSuccess', It terminates the program-- successfully.exitSuccess::IOaexitSuccess=exitWithExitSuccess